Numerous industrial processes generate waste material. Some types of waste material are hazardous to the environment by virtue of their dangerous chemical or physical properties. Such hazardous waste materials include radioactive wastes, carcinogens, chemical insecticides and pesticides, acids, corrosives, active metal compounds, nerve gases and materials contaminated by such substances. In order to prevent such waste materials from damaging and contaminating the environment, it is necessary either to render the materials harmless or to isolate the materials from the environment in a waste storage facility.
High level radioactive waste materials generated by the operation of nuclear reactors in nuclear power plants are especially dangerous due to the high levels of radioactivity which remain present in the radioactive waste materials for many, many years. Some of the radioactive isotopes in the spent fuel elements of a nuclear reactor or in other high level radioactive waste materials have very long half lives. The leakage of such radioactive waste material could cause long-term radioactive contamination of the environment. An additional problem that arises in the storage of high level radioactive waste materials is the problem of disposing of the heat from the decay of the radioactive isotopes in the stored high level radioactive waste materials.
A similar problem arises with respect to low level radioactive waste materials including numerous radioactive isotopes used in medicine and scientific research. Although such low level radioactive waste materials may exhibit a lower level of radioactivity and heat production than high level radioactive waste materials, such low level radioactive waste materials still pose the threat of long-term contamination of the environment. In addition, when large quantities of such low level radioactive waste materials are stored in the aggregate, the cumulative levels of radioactivity and heat production are not insignificant.
Although the apparatus and method of the present invention may be used to monitor the storage of all types of hazardous and non-hazardous materials, it finds one of its most useful applications in connection with the monitoring of the storage of radioactive waste materials. The continued operation of nuclear reactors will generate an ever increasing amount of high level radioactive wastes in the form of spent fuel elements. Presently, such high level radioactive wastes are being stored in various underground sites such as caves. The possible dangers of environmental contamination inherent in unmonitored underground storage can be avoided if the radioactive waste materials are stored and monitored using the apparatus and method of the present invention.